Cam belt replacement - Help!

Hi

I'm completely ignorant in field of car maintenance and wonder if anyone can shed any light? I've a 2002 Clio Expression 1.4 Automatic which has done about 32k miles, a mixture of local and motorway driving. It's due a service now and I've been told that the cambelt should be replaced after 72k miles or every 5 years (now just over 5 years old). I've been quoted £230 for service plus £549 for cambelt replacement. I feel that they might be ripping me off! Any opinions? Does it need replacing? Does being automatic and having air-con make a difference in cost? What should a fair price be?

Thanks

Theresa

Just had cambelt replaced on diesel expession dci for £70 plus £20 for belt.
However this was not a garage but a mechanic who works in a garage on his own time. Check around for someone in this position if you can as you can see the garages definately are ripping people off!!!
And yes cambelt does need replaced after 50-72K, if left it can lead to complete engine failure apparently.
Not sure it having an automatic makes any real difference